new 331 build need some help with cam selection.

djbuchanan

New Member
Oct 21, 2007
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hey every one, i just got back from deployment finally got some money in my bank to work on my car again. the engine sadly spun a rod bearing over a year ago and has been sitting since. its a 66 coupe, 9 inch rear 3.55, PA c4 tranny with 3000 stall. im just putting together the pieces now, i have a 331 bottom end with forged flat top pistons, cast crank and forged i beams, sitting in a dart SHP block. i have a set of edelbrock rpm heads with2.02 valves left over, vic jr intake and a 750 carb lying around from the old 302.

i intend on swapping out the heads later on with afr 185's. but for now im just gonna use the rpms for money reasons. im looking for a hyd roller cam thats a little more than mild but enough that i can still drive when i get stuck in the san diego traffic and hills. the intentions are something i can lay down low 11's and somewhere a little below 500 hp and tq. not a daily driver, just a weekend car. sorry about the page long intro guys.

ps. any other input on the build is welcome.
 
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I think the 331 might be pushing it to hit 500hp unless youre talking fwhp and not rwhp, or unless everything in the combo matches perfectly. Youre certainly starting in a good place going with the dart block though - at least you wont have to worry about it all flying apart.
 
I was in your position when building my engine and I wanted to find a cam that would make the most horsepower that would suit my needs. I had purchased an Anderson Ford Motorsport B-31 cam a few years ago and have been extremely happy with the performance. I recently was building another engine for my 67 Cougar XR7 I'm currently working on and I wanted to know if I should purchase a different cam or use the same AFM B-31 cam I already had. Well, I have the Dyno 2000 program and the Comp Cams Cam Quest program and I compared all kinds of cams from different companies (AFM, Ford Motorsport, Comp, Crane, Edelbrock, Trick Flow) and much to my delight the AFM cam made the most overall horsepower over the broadest range.

My point is that if I were you I would check out the cams from Anderson Ford Motorsport (andersonfordmotorsport.com). They seem to make great cams that produce great horsepower. Just my 2 cents...
 
first in my opinion the edelbrock heads are better than the afr185 heads so dont spend any money on the heads, except perhaps to port the edelbrocks

as for the cam, the first thing you want to do is decide what rpm range you are going to run in about 80% of the time, and select a cam that works in that rpm range. you can fudge it a bit one way or the other with your combination. for instance lets say you decide that you want the engine to make its best power in the 2000-6000 rpm range. you can select a cam that works in that range, or one that works in a slightly higher range, say 2200-6500 for instance, or a slightly lower range 1800-5800. keeping that in mind, a friend of mine and i built a 350 for his Z28, and we used an xe268h cam in that engine. it works quite well for his combination. start there, but also look at cams like the comp cams 280 magnum or the xe274h.
 
I'm running a Ford Z303 with 1.7 rockers in my 331, but with a dual plane 3x2 intake and carbs. Power comes on at 1500 and pulls to a bit past 6500. Plenty tame enough for daily driving, but at the same time has a healthy lope idling at 500 rpms. The converter in the C-4 behind it is no where close to a 3000. More like in the 1500-2000 range. The Comet runs high 12's-low 13's with 3.50's and 295/50 street radials.
 
I'm running a Ford Z303 with 1.7 rockers in my 331, but with a dual plane 3x2 intake and carbs. Power comes on at 1500 and pulls to a bit past 6500. Plenty tame enough for daily driving, but at the same time has a healthy lope idling at 500 rpms. The converter in the C-4 behind it is no where close to a 3000. More like in the 1500-2000 range. The Comet runs high 12's-low 13's with 3.50's and 295/50 street radials.

What heads are you using on this engine? How about compression? Are you using any power adders (supercharger, turbo, nitrous)? Just wondering what combination you're using to run 12's with a street car? What year is your Comet? How well does your 3x2 carb setup run? Any streetability problems? How hard were they to tune?
 
edlbrock heads better than afr's? maybe the vic jr is better than the afr 165 but the 185 will make more overall power on a 331......off the shelf cam wise the comp xe274hr, xe282hr (pretty hot in a 331) or the lunati 61012 voodoo cam ( still slightly hot), look at the cnc twisted wedge heads as well, you can make more power and way better low end on the small 331 with them over the afr's, the TW heads have much better low-mid lift flow numbers even wit smaller ports yet big flow up top as the rotated intake valve is closer to the CC and has a larger cross section than bigger port heads.
 
What heads are you using on this engine? How about compression? Are you using any power adders (supercharger, turbo, nitrous)? Just wondering what combination you're using to run 12's with a street car? What year is your Comet? How well does your 3x2 carb setup run? Any streetability problems? How hard were they to tune?

Canfield's equivalent to AFR165's. Comp ratio is 10.4 to 1. Heads were milled .060 for a previous build (64 ccs down to 57) No power adder. It's a 77 Comet. The 3x2's are THE best street intake/carb combo I've ever used. I built this engine and tuned the carbs 6 years ago. Ain't touched the carbs adjustments since. Tuning took all of an hour, mainly just changing the jets. Went from 58's in all three (Holley 250 cfm 2 bbls) to 60 primary/62's in the secondaries. No problems with the setup, whatsoever. It's one from Mustangs Unlimited, bought it second hand from a guy in Indiana, it was a year old when I got it.
 
i actually just left jays site, ive been looking at it for a pretty long time..( got the car out of a junkyard when i was 15, 22 now) pretty much just trying to rationalize dropping the dough for a custom grind, then lifters, reconfiguring my springs if needed. good news though, just got the short block dropped off at my parents house back in md. waiting take leave and start putting things together..as for the heads how much do you think i could really benefit with having them ported. as to just waiting it out till another day with money(the corps sure doesnt pay much) ive been trying to compare the comp cams xe 274 or xe 284.. just by going by my stall speed. the 274 matches the heads better but considering my intake, and stall speed i dont see how much the 284 slightly higher power band could adversley effect me.
 
I just ordered a cam from Jay and it was a bit expensive but should be worth it. I have already purchased 2 cams and did not like the results. I figure it is better to have a guy that knows what the hell he is doing (I don't when it comes to cam selection) make me what I need. Give it another thought before you dismiss it. s b f tech dot com has a section for OTS cams you may want to look at.
 
i actually just left jays site, ive been looking at it for a pretty long time..( got the car out of a junkyard when i was 15, 22 now) pretty much just trying to rationalize dropping the dough for a custom grind, then lifters, reconfiguring my springs if needed. good news though, just got the short block dropped off at my parents house back in md. waiting take leave and start putting things together..as for the heads how much do you think i could really benefit with having them ported. as to just waiting it out till another day with money(the corps sure doesnt pay much) ive been trying to compare the comp cams xe 274 or xe 284.. just by going by my stall speed. the 274 matches the heads better but considering my intake, and stall speed i dont see how much the 284 slightly higher power band could adversley effect me.

First you've got to ask yourself where you want the engine to make power. With a Vic Jr, it's not going to start making power (what I call "come on at") less than 2500-3000 rpms. And the bigger the cam you go with, the higher that point's going to be. With a dual plane intake, the power's going to start a a lot lower rpm, like mine does at 1500. So in effect, with the Vic jr, it's going to feel weak till it hits that point. I've built one motor with a Vic Jr. It was fun for about a week. Motor lasted about a month and a half before splitting a cylinder wall at 7500 rpms. My 331's doing the deed now for about 6 years. It's been regularly to 6500, and up to 7 grand several times. Sure, it's nice to brag about making power in the upper stratosphere in the rpm range, but motors that do this don't last long. And aren't very fun on the street for daily driving.
 
I have a very similarly built 347 in my '66 Coupe (AFR185's, Vic Jr intake, 750 carb, 3.55 gears) and I went with a Cam Research solid flat tappet cam. At the time I didn't want to change valve springs/retainers/etc. so I just had them make it to work with my springs. So I kept lift under .550 and duration is in the 230 area @ 0.050. It was a bit of a comprimise on my part at the time but it has my Mustang running as quick as 11.3's so far. It's nowhere near 500 hp but it feels pretty responsive and will even spin a tire if I try hard enough:nice:
 
If you want to do your engine a favor just remember that a solid roller will always be the HP champion and the hydraulic flat tappet will always be the low man on the scrotum pole. Of course the other 2 choices fall in between these 2 and both can make great power IF you make the right choice.
 
honestly, I would say the xe274 (or trick flow stage 2).

not enough gear or converter to use something that makes peak at 6500.

If it were mine, I would decide on using the gear/converter and dropping to a RPM airgap or what-have-you OR keeping the intake, going with a xe282, and stepping up the gear and stall some.
 
But the edge it gives will be in the upper rpms. Something not always needed in a street motor. You've got to think about this, how much time will actually be spent in the 6000-7500 rpm range ?

My car is a street/strip car and every pass I make at the strip it sees 6500 rpm.
If I had a 331 stroker sitting in a Dart block I would not crutch it with a hydraulic flat tappet cam. Solid lifter cams will definitely shine in the 6000 rpm and up range. There is huge power to be had in the upper rpm range. With that sweet block and the correct valvetrain I would not hesitate to rev this thing to 7 grand. The car will be MUCH faster with a solid cam running to 7 grand than with a hydraulic running to 6 grand.